Mold Linker Has Switched to Rust
The release of version 3.0 moves the project from C++ to Rust to improve memory safety and Linux compatibility.
Updated on Oct. 5, 2026 in Software
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Developers have released Mold 3.0, a high-speed linker now entirely rewritten from C++ to the Rust programming language. This new version replaces the final C++ iteration, Mold 2.42.1, while introducing a new build system.
Why it matters
The transition to Rust is intended to improve safety when processing potentially corrupted input files while closing compatibility gaps with the GNU LD linker. These changes aim to move the software toward potential adoption as a default linker for Linux distributions.
Mold 3.0 requires Rust 1.95 or later and has moved from the CMake build system to Cargo. The project has also removed its prior dependency on Intel oneTBB.
The players
Mold
A high-speed linker designed for Linux environments that aims to replace traditional GNU LD implementations.
The details
The linker—a utility that takes compiled object files and binds them into a single executable or library—has been completely rewritten from C++ to Rust. This shift aims to leverage Rust's memory safety guarantees to handle malformed input files more robustly than the previous C++ codebase. The build process now uses Cargo, the standard package manager for the Rust ecosystem, replacing the legacy CMake configuration.
Timeline
Mold 3.0 was released on 2026-10-05.
The Tech Race
This story follows the precedent set by the integration of Rust into the Linux kernel, aligning developer efforts toward memory-safe systems programming. The rewrite positions the project to compete more effectively with the legacy GNU LD standard by addressing long-standing technical debt.
Users upgrading from Mold 2.42.1 must ensure their environment supports the Rust 1.95 toolchain. Developers building on Linux should monitor future 3.x releases for improved GNU LD compatibility milestones.
The takeaway
The move to a memory-safe language represents a significant architectural pivot for core system utilities. Watch for upcoming 3.x updates to see if the project successfully achieves parity with GNU LD, a critical requirement for wider adoption.
Further reading
For more background on the evolving standards for build tools and system performance, visit the Software archive.
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